Table 1. Constraints on restoration of downstream wetlands, and recommended policies for landscape-change adaptation.

Scale of constraints Restoration challenge Policy recommendations
Globe
 
Rapidly rising sea level, climate extremes, nitrogen mobility
 
Preparedness: predict future conditions; aim high but do not expect to recreate historical levels of biodiversity and services; envision alternative scenarios; field tests will indicate that some targets are unachievable
 
Watershed
 
Excess water, eutrophication
 
Create strategic watershed plans that identify watershed needs and then prioritize restoration of potentially restorable sites and expected levels of each service; track impacts in downstream wetlands; conserve or restore diversity upstream; compare outflowing water from watersheds ± substantial restoration to assess effects of restoration
 
Site
 
Poor substrate, invaders
 
Shift target from restoration of historical states to adaptive restoration; aim high but use field experiments to rule out targets that cannot be achieved
 
Biota
 
Fewer species and smaller gene pools
 
Retain and restore habitat for declining species where it occurred historically, where it might be achievable, near remnant populations, and in sites near one another; establish matrix dominants first, then test a site’s ability to support diverse species and genotypes
 
Assessment needs
 
Insufficient monitoring
 
Plan for clear and objective assessments; assess sites at intervals using objective indicators for abiotic and biotic components and services; set standards a priori; use data to judge progress at intervals, over long time periods